136 



INVERTEBKATA 



CHAP. 



cell 2b 2211 , and an inner and lower cell 2b 2212 whilst 2l> 222 divides into 

 two sisters lying side by side, viz. 2b 222r and 2b 2221 . Now these four 

 cells in quadrant I>, and the two cells in quadrant A, viz. 2a 221a and 



2 



Fio. 103. (Continued on opposite page.] 



2a 222a , and in quadrant C, viz. 2c 221a and 2c 222a (Fig. 103, C), are destined 

 to form the stomodaeum, Itut for the complete history of this 

 structure we must wait until we have considered the history of the 

 third quartette of micromeres. 



